Thomson Reuters This past year, the Zika virus has emerged as global problem.

The virus, which is primarily transmitted via mosquitoes, has been spreading around the Americas since May 2015. One of the reasons it's been so troubling is that it's a cause of a serious birth defect called microcephaly, in which the head of babies whose mothers have been infected with Zika during pregnancy are abnormally small. That's tied to a number of developmental problems.

As with many emerging diseases, the misinformation about Zika started circulating almost as quickly as the disease itself.

We're still learning more and more about the virus and how it affects people, but for now here are some of the biggest myths and misconceptions we've heard about Zika.

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MYTH: GMOs are to blame for the recent Zika outbreak across the Americas.

Diseases like Zika, dengue, and yellow fever are spread by a mosquito called Aedes aegypti. To try and stop the spread of disease, scientists have started looking into how to quell mosquito populations.

One interesting idea to fend off the disease-carrying bugs comes from a company called Oxitec, which genetically modifies male mosquitoes to carry a lethal gene. Those bugs mate with female mosquitoes and pass on the gene, which kills little baby mosquitoes before they ever mature into adults. As the modified bugs breed more and more, the mosquito population shrinks overall.

MYTH: Zika can spread by kissing.

While there have been cases of sexually transmitted Zika, both from male to female, male to male, and female to male, for the most part it is still spread by mosquitoes, who pick it up from the blood of one individual and transmit it to another.

"It's a disease transmitted through sex, but certainly at this point we wouldn't carry it to say it's a sexually transmitted disease," Dr. Robert Segal told Business Insider during a Facebook Live session.

So far, public health officials believe the main ways it could be transmitted are through blood (either mosquito or possibly blood transfusion), semen or vaginal fluid, or while a mother is pregnant.

MYTH: Pesticides are responsible for Zika.

A health worker fumigates as part of preventive measures against the Zika virus and other mosquito-borne diseases, at the cemetery of Presbitero Maestro in Lima
Thomson Reuters

Another conspiracy theory about the most recent Zika outbreak hit the internet in February. It claimed that a pesticide being used to kill mosquitoes was linked to the cases of microcephaly, not the Zika virus itself.

The chemical, Pyriproxyfen, messes with the hormones that help mosquito larvae hatch (an exchange that doesn't happen in human births). Plus, it doesn't absorb into our bodies that well. "A person would have to drink well over 1,000 liters of water a day, every day, to achieve the threshold toxicity levels seen in animals," Ian Musgrave, a senior lecturer in the medical school at the University of Adelaide in Australia, said in February.

MYTH: Zika symptoms look a lot like the flu.

A pregnant woman looks on as mosquito nets are used at the Women National Hospital in an effort to prevent being bitten by mosquitoes that might carry Zika, Dengue and Chikungunya viruses, in San Salvador, El Salvador.
Reuters/Jose Cabezas

It's true that Zika and the flu share some similar symptoms, namely fever and muscle/joint pain. But there are some clear differences, as explained by the World Health Organization. Namely, in most people, Zika symptoms will be nonexistant or much milder than a run-of-the-mill flu.

From the WHO (emphasis ours):

"Seasonal flu can cause severe illness or death. The disease is characterized by a sudden onset of high fever, cough (usually dry, can be severe), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and runny nose.

"Zika virus disease usually causes mild illness, and most people will not develop any symptoms. The most common symptoms of Zika include low fever or rash, conjunctivitis, muscle and joint pain, appearing a few days after a person has been infected by an infected mosquito or after sexual intercourse with an infected person. However, there is scientific consensus that Zika virus is a cause of microcephaly and Guillain-Barré syndrome which can be a fatal condition."

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MYTH: The birth defects associated with Zika are caused by vaccines.

A nurse prepares a vaccine to be given to a child.
Thomson Reuters

As people tried to pin the birth defects associated with the current outbreak of Zika on something, the theory that vaccines given to mothers during pregnancy could play a role in the birth defects that are linked with Zika. But that's been refuted.

"There is no evidence linking any vaccine to the increases in microcephaly cases that were observed first in French Polynesia during the 2013-2014 outbreak and more recently in northeastern Brazil," the WHO said in a statement. "An extensive review of the literature published in 2014 found no evidence that any vaccine administered during pregnancy resulted in birth defects."

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Here's what we do know.

There's still a lot that we still need to figure out about Zika.

It's a virus that's been around since 1947, but the strain associated with the most recent outbreak and the one before that in French Polynesia are the first to be connected to birth defects and other serious complications including Guillain-Barre Syndrome.